wow, that is one helluva break in a ‘lightly used’ paddle. If it breaks like that, one’d expect similar potential failure at the other end – and would question if even worth fixing.
However, there it is . . . so if one was to fix, I’d lay up a form [in clay, foam, concrete, or wood bits] using the other half of the paddle end [will have to modify/fudge somewhat if non-symmetrical blades], then dig out the foam from each broken pc for as long as possible [say 2″ [5cm] each side – longer if possible] and make a really loose fit tenon out of softwood [spruce or cedar], butter the tenon with resin-ed diagonal glass pulled to linearize the fibres, and jam everything together into the previously made form and at the feather angle you wish.
Let set up, sand 3″ [7.5cm] in ea direction and lay on 2 lyrs of 6oz, let set up, sand to your desire. Then add say amt glass on the other end to mimize the same happening over there.
And then use paddle for easy paddling and lend-outs.
idea, anyway.